Best way to put out an offer

[Angel Peng]

I found a quadplex for $390k. It has so much traffic and popularity just 2 hours of being placed on Zillow. This is my first investment property. I will be doing a conventional 20% down. I am willing to go as high as $480k for this place. How should I make this offer? Should I offer starting at asking price with an escalation clause of $3000 higher than the highest bidder until $480k? And I would require that they show the price of the 2nd highest bidder. 

Another offer would be that I start at $420k with the same escalation. 

Or should I just start at $430-450k to begin with. 

I am willing to go as high as $480k but obviously would like to avoid it if I could do it for much lower. 

Thank you all for your expertise.